The present invention relates to a method and a system for verification of the presence of living poultry embryos in incubating poultry eggs.
About 10% of all eggs reaching chick hatcheries are non-fertile. For both economic and hygienic reasons, the hatcheries are interested in eliminating these eggs at the earliest possible opportunity. The conventional process used to this end is known as xe2x80x9ccandlingxe2x80x9d. In this process, on about the 10th day of incubation, an experienced operator in a darkened room manually passes a strong light source from egg to egg and looks for a network of tiny blood vessels in each now translucent egg. This network indicates a developing embryo. Eggs lacking this network are immediately discarded, as they obviously will not end up as chicks and, at this stage, are no longer fit for human consumption.
The time-honored method of candling has several serious disadvantages. It requires trained manpower (large hatcheries incubate tens of thousands of eggs at any given time), yet even the most experienced operators will fail to correctly diagnose one out of every ten eggs. The operators will either fail to recognize the capillaries or they will pass as fertile an egg in which the capillaries are still discernible, thus giving the appearance of a properly broodable egg, when in fact the embryo has died.
In recent years, attempts have been made to increase the low efficiency and reduce the high demands for operator skill of the candling process by introducing devices built around optical systems that, to some extent, could also be automated. Yet while these improved candling devices could, with some reliability, differentiate between fertilized and non-fertilized chicken eggs, they fail to distinguish between fertilized eggs containing a live embryo and eggs which, although still displaying the capillaries, contain embryos that have died. Furthermore, these optical devices are altogether unsuitable for checking turkey eggs which have shells that are thicker and far less translucent than those of chicken eggs.
It is thus one of the objects of the present invention to provide a method for verification of the presence of living poultry embryos in incubating eggs. This method is not based on the expertise of human operators, has a much smaller error margin, and can be largely automated.
It is a further object of the present invention to provide a method that will pick out for discarding not only non-fertilized eggs, but also originally fertilized eggs in which the embryo has died.
It is a still further object of the invention to provide a method for handling turkey eggs which have shells that are much thicker and far less translucent than those of chicken eggs.
These objectives are achieved by providing a method according to the present invention for verification of the presence of a living embryo in an incubating poultry egg. This method comprises the steps of: causing at least two electrodes to make conductive contact with the outside surface of the shell of said egg; amplifying any of the analog signals received via two of the at least two electrodes; analyzing the signals after amplification, using a program in a microprocessor, to establish whether the signals originated in the cardiac activity of the embryo; and providing information confirming or negating the presence of a living embryo in the egg.
A system is also provided according to the present invention for verification of the presence of a living embryo in incubating poultry eggs. The system comprises: an array of detector heads, each provided with at least two electrodes adapted to make contact with the surface of the shell of one of the eggs; a microprocessor responsive to signals received by the electrodes and adapted to establish the presence or absence of signals originating in the cardiac activity of a living embryo; and means controlled by said microprocessor to facilitate separation of the eggs found lacking such a presence from those in which such a presence has been confirmed.
The invention is based on the fact that the cardiac activity of the embryo produces characteristic electrical signals as early as at the end of the third day of incubation. By amplifying these signals, picked up by non-invasive electrodes that leave the eggshell intact, and analyzing them after separating them from the inevitable noise superposed on them, proof can be obtained not only that the egg has been fertilized, but also that it contains a live embryo. Conversely, the absence of such signals signifies a non-fertilized egg or a dead embryo in an originally fertilized egg.